The present invention relates to a circuit for supplying a control contact with power and the application thereof to the control of a rest time delay of a relay.
When it is desired to use a contact for controlling a function on an apparatus fed with AC or DC, comprising components which may be electronic or not requiring a power supply and at least one control signal and working over a wide voltage range (24 V to 240 V for example), it is necessary to have good contact reliability for the control contact, to have flowing therethrough a current of a minimum intensity of the order of about 10 mA for a standard contact.
On the other hand, to control an electronic circuit, it is not necessary to have currents of high intensity. A value of the order of a milliampere may be sufficient, as the circuits are voltage-controlled. Moreover, it is known, if it is desired to work in a large voltage range, to include a series of dropping resistors which will be connected by means of jumpers so as to maintain the current in the contact at an acceptable value without however dissipating too much energy in the control circuit.